No one uses this service because:
1. The account can be recovered.
2. It can be reported as hacked.
3. If they ask any verification at any stage you cant provide verification document.
4. Content style of the account and your creating content might not be the same.
5. As OP will deliver once s/he receives the fund so, you may not receive the channel.
6. If any stage they suspend your account you cant recover as you are not the real owner.
There might have many more reasons, so stay away and be safe.
1. The account can be recovered.
2. It can be reported as hacked.
3. If they ask any verification at any stage you cant provide verification document.
4. Content style of the account and your creating content might not be the same.
5. As OP will deliver once s/he receives the fund so, you may not receive the channel.
6. If any stage they suspend your account you cant recover as you are not the real owner.
There might have many more reasons, so stay away and be safe.
Lol
, these accounts selling like crazy on internet 
. please before bad things , look internet . I just wanted one more topic on one more forum. That's it. I can use middleman as i see. and it cant be hacked you will change account details and if you still dont trust youcan activate 2 step verification:) 